According to an interview with the Recode, Instagram's executive Vishal Shah said that their focus is to help sellers find ways to advertise on the main app. The vision behind a standalone app is to create a channel within the existing app ecosystem. Instagram is not keen to introduce another app and bother its consumers by asking them to download it again.
From what we make of this, Instagram will have a major section within the main app, similar to IGTV, which caters to those who might want to shop for products they come across in the app.
He said, "It’s the equivalent of walking down the street on the way to dinner and seeing an interesting product in the window, and then walking in. You didn’t set out to shop. You just came across a product. That’s what I think feed and Stories really does well."
Instagram's consumer base are those users who are actually looking to spend on products via Instagram rather than just 'window-shopping'.
Instagram will introduce business stickers for all business Stories and their feed with a focus on selling products.
Earlier this year in June, Instagram had extended the shopping feature to its Instagram Stories as well, where businesses could add a link to their Stories which takes users to the business' shopping website.